A new way to generate multi-watt-level, octave-spanning, spectrally flat supercontinua

A team of researchers led by Asst. Prof. Bülend Ortaç (UNAM) has published an important study in Nature Scientific Reports journal. In this study, Ortaç group proposed a novel method to achieve octave-spanning spectrally flat supercontinuum with world record output powers.

High power supercontinuum light sources are essential for microscopy and metrology measurements. So far supercontinuum generation studies in the literature are focused on photonics crystal fibers but these fibers are hard to produce and expensive. Very recently, Ortaç Group’s efforts on multimode nonlinear fiber optics revealed various dynamics such as femtosecond spatiotemporal instability and multimode interference-based saturable absorber – bandpass filter devices which enabled the development of one of the simplest all-fiber laser cavities. As a continuation to these studies, Ortaç Group proposed a novel supercontinuum generation method based on cascaded Raman scattering phenomenon in graded-index multimode fibers.

In the study just published, researchers exploited the cascaded Raman scattering effect which is a unique feature of graded-index multimode fibers to achieve octave-spanning spectrally flat supercontinua. Experimentally verified results present the highest output average power in the literature obtained from multimode fibers. Power scalability of the proposed method promises that tens of watts output average power will be feasible by just scaling the pump pulse powers.

Researchers involved in this project are Uğur Teğin and Bülend Ortaç. The open-access article is available online on the Nature Scientific Reports website: https://www.nature.com/srep/